Perception of Gravity by Roots of Vicia Faba

Abstract

UNTIL recent years it was a generally accepted view that the region of perception of gravitational stimuli in roots was the extreme tip of the root. Cholodny,1 however, performed experiments in which he replaced the root tip in maize by the tip of the coleoptile, and the fact that a positive curvature was still obtained suggested that the function of the root tip might not be so simple as had hitherto been supposed. More recently, Keeble, Nelson, and Snow2 performed experiments in which positive geotropic curvatures were obtained when unstimulated root tips were stuck on to stimulated root stumps which had been decapitated before stimulation.